The number 16281
16281 is a composite number with 12 divisors. Its prime factorisation is × 67. Divisors (12): 1, 3, 9, 27, 67, 81, 201, 243, 603, 1809, 5427, 16281.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
16281 has no famous special property in the usual lists (prime, square, cube, triangular, Fibonacci, palindrome, perfect), but it is still a composite number.
- 2
16281 is composite. Its prime factorisation is
- 3
The divisors add up to 24752; without 16281 itself that is 8471, so 16281 is deficient (8471 is less than 16281). Euler's totient φ(16281) = 10692 numbers up to 16281 share no factor with it.
- 4
The digits of 16281 add up to 18, and repeating that until one digit is left gives the digital root 9. The Collatz sequence (halve if even, else 3n+1) takes 115 steps to reach 1.
LaTeX source of the formulas on this page
\[ 16281 = 3^{5} \times 67 \]16281 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 12 |
| Sum of divisors | 24752 |
| Euler totient φ(n) | 10692 |
| Square | 265070961 |
| Cube | 4315620316041 |
| Square root | 127.597022 (= 9√201) |
| Digit sum / digital root | 18 / 9 |
| Collatz steps to 1 | 115 |
| Scientific notation | 1.6281 × |
16281 in other forms
| Form | Value |
|---|---|
| In words | sixteen thousand two hundred and eighty-one |
| Binary (base 2) | 11111110011001 |
| Octal (base 8) | 37631 |
| Hexadecimal (base 16) | 3F99 |
| Base 3 | 211100000 |
| As time | 16281 seconds = 4 h 31 min 21 s |
Is 16281 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | No (remainder 1) | A number is divisible by 2 if the last digit is even (0, 2, 4, 6, 8). |
| 3 | Yes (16281 ÷ 3 = 5427) | A number is divisible by 3 if the digits add up to a multiple of 3. |
| 4 | No (remainder 1) | A number is divisible by 4 if the last two digits make a multiple of 4. |
| 5 | No (remainder 1) | A number is divisible by 5 if the last digit is 0 or 5. |
| 6 | No (remainder 3) | A number is divisible by 6 if it is divisible by both 2 and 3. |
| 7 | No (remainder 6) | A number is divisible by 7 if double the last digit and subtract it from the rest: the result is a multiple of 7. |
| 8 | No (remainder 1) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | Yes (16281 ÷ 9 = 1809) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | No (remainder 1) | A number is divisible by 10 if the last digit is 0. |
| 11 | No (remainder 1) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 9) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 16281 a prime number?
No. 16281 = × 67, so it is divisible by 3.
What are the factors of 16281?
1, 3, 9, 27, 67, 81, 201, 243, 603, 1809, 5427, 16281.
What is 16281 in binary?
11111110011001 (hexadecimal 3F99, octal 37631).
What is the square root of 16281?
About 127.5970, exactly 9√201.
Is 16281 divisible by 3?
Yes. Its digits add up to 18, a multiple of 3.
What is special about the number 16281?
It is a composite number with 12 divisors.